Of the essays here presented for the reader’s attention, some are published for the first time, others appeared in various periodicals before the war. They deal with a question which now, naturally, arouses especial interest—the significance and role of national movements, the relationship between the national and the international. The biggest drawback, one most frequently encountered in all the arguments on this question, is lack of concreteness and historical perspective. It has become customary to smuggle in every manner of contraband under cover of general phrases. We believe, therefore, that a few statistics will prove anything but superfluous. A comparison with the lessons of the war of what we said before the war is not, in our view, unuseful. Unity of theory and perspective gives the essays continuity.